The present invention generally relates to a system for controlling the operation of a combined central locking system and burglar alarm system, and more particularly to a control system which provides an authorized user with a simple, convenient capability for operating both systems from a single locking point by a designated key.
Combined central locking system and burglar alarm system arrangements are known. Such an arrangement is disclosed in German Patent (DE-PS) No. 35 16 732, which provides for the convenient and uniform control of both the central locking system, as well as the burglar alarm system, via a single locking point on at least one door, the burglar alarm system being controlled by the same switching contact as the central locking system. When the central locking system is locked by a particular key at the designated locking point, the burglar alarm system is automatically activated, i.e., switched ready for alarm. The burglar alarm system is deactivated when the central locking system is unlocked by this key at the designated locking point. However, the above-referenced German patent fails to provide for the deactivation and resetting of an alarm which, in particular, has been accidentally tripped by authorized users.
A burglar protection system with an additional switching device for clearing an alarm tripped by an operating error is disclosed by German Patent (DE-PS) No. 29 15 213. Overall control of this system, both activation and deactivation of the system, as well as clearing the alarm after accidental activation by an authorized user, can only be effected from the passengers' compartment of the motor vehicle. The clearing and resetting operation is effected by the simultaneous operation of two different keys of a key pad arranged on the dashboard of the motor vehicle. A relationship between the operation of a central locking system and the alarm readiness of the burglar protection system is not considered in German Patent (DE-PS) No. 29 15 213.
Accordingly, it is an object of the present invention to provide a combined central locking system/burglar alarm system arrangement for shutting off an accidentally tripped false alarm and for furnishing authorized vehicle users with a simple, convenient capability for unambiguously determining the vehicle protection status.
In accordance with one embodiment of the present invention, there is provided a control system for controlling both a vehicle central locking system and a vehicle burglar alarm system from at least one locking point of the central locking system when operated by a designated key. The control arrangement comprises a lock contact for providing indicating signals representing a position of a lock associated with the at least one locking point as well as a switch for providing a detection signal in response to the presence of the designated key at the at least one locking point. A burglar alarm control device deactivates an unintentionally triggered alarm in response to a detection signal indicating the presence of the designated key at the at least one locking point and then arms the burglar alarm if the locking point is locked and disarms the burglar alarm if the locking point is unlocked in response to the indicating signals from the lock contact. A switching device selectively connects the control device of the burglar alarm system to the locking point in response to a detection signal indicating the presence of the designated key at the at least one locking point.
In accordance with another embodiment of the present invention a time delay is established after an unintentional alarm has been deactivated and before the burglar alarm control device is connected to the lock contact by the switching device.
In yet another embodiment of the present invention, the switching device connects the control device to a plurality of locking points after an unintentional alarm has been deactivated in order to determine the desired activation state of the burglar alarm system.
The system according to one embodiment of the invention enables the vehicle user to deactivate a false alarm from outside of the vehicle using his vehicle key or the designated key.
In yet another embodiment of the invention, deactivation of the false alarm can occur upon the insertion of the key in the lock or during subsequent rotation of the key by a relatively small angle, since in the latter instance it is only a matter of operating an electric microswitch arranged at the locking cylinder.
One advantage of the connection of the control device of the burglar alarm system by the switching device to the lock contact(s) of the central locking system control for the renewed synchronization of the central locking system and the burglar alarm system is that a short time after the alarm has been cleared, the user of the vehicle can visually determine, from the position of the internal locking knobs of the doors, whether the vehicle is unlocked or locked. He can rely on the fact that the burglar alarm system is activated when the vehicle is locked. A brief waiting time before the control device is connected by the switching device to the lock contacts ensures that any locking or unlocking process of the central locking system, which may have been triggered with the rotation of the key, is completed before the burglar alarm control device is connected to a locking point. However, the waiting time is not absolutely necessary if only the lock contact associated with the alarm-clearing locking point is connected to the control device by the switching device. This system can be simply integrated into the burglar alarm system control device. Naturally, this is unnecessary if only one locking point is provided with associated lock contact and electric switch as a minimum equipment.
The advantages of the generic combined central locking system/burglar alarm system, particularly also the use of the advantageous main key/auxiliary key system, are retained.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.